Final answer:
Regulation of body temperature is not a function of the digestive system, which is tasked with digesting food, absorbing nutrients, and eliminating waste.
Step-by-step explanation:
The function that is not a part of the digestive system is c) Regulation of body temperature. The digestive system has three main functions which include: digestion of food, absorption of nutrients, and elimination of solid food waste. Digestion involves both mechanical and chemical breakdown of food, enabling the body to absorb nutrients. Mechanical digestion is the physical breakdown of food, while chemical digestion involves the enzymatic breakdown into absorbable molecules. Absorption occurs primarily in the small intestine, where nutrients enter the bloodstream. Lastly, waste elimination is the process of expelling indigestible food components from the body.